Radish sprouts, like other varieties of sprouts, are becoming an increasingly popular food item. Radish sprouts are highly nutritious and, for example, may be used as a condiment for salads. Radish sprouts are grown from radish seeds which mature into edible seedlings.
It is most difficult to harvest automatically radish seeds from mature radish plants because the plants produce the seeds in a hard pod or shell. This is especially true of the Diakon variety, a desirable variety of radish which produces a particularly hard pod.
There are mainly two reasons for this difficulty. First, the radish pods containing the seeds have no natural fracture line, like many other seed-containing pods, such as beans and peas. Second, it is critical that the seed itself not be damaged during the harvesting process. Even a hairline crack in a harvested radish seed results in an unattractive, and therefore undesirable, black ring on the cotyledon leaf of a radish seedling grown from the seed. From a commercial standpoint, it is highly desirable to limit defective seeds to 2% or less of the total number of seeds harvested. In any event, a harvested crop having more than 5% defective seeds is unacceptable.
Conventional harvesting combines are ineffective in harvesting radish seed. Such combines typically include a wide pick-up conveyor at its forward end to pick-up the radish windrow, followed by an auger which breaks up the cut radish plants comprising the windrow and moves the same to a feeder conveyor. The feeder conveyor conveys the seed-containing plants to a thresher having a thresher bar and concave closely surrounding the thresher bar. The thresher bar rubs the radish plants against the concave to separate the chaff from the remainder.
The thresher generally falls into one of two types. The most conventional type has a wide cylindrical threshing mechanism that is belt or chain driven. Alternatively, the thresher may have one or more longitudinal rotors that extend much of the length of the combine. The latter type is sometimes referred to as an "axial flow" or "rotor" type thresher. While both such threshing mechanisms adequately separate the seed-containing radish pods from the chaff, they are of little, if any, use in separating the seeds from the pods.
One modification of a conventional combine that has met with some success in harvesting radish seed is the use of rubber-coated "flax rolls" to split open the radish pods before they enter the thresher, thereby to enable the thresher to separate the exposed seeds from the pods. The term "flax rolls" comes from the traditional use of similar rolls to abrasively remove flax seed from harvested flax. One of the rolls is typically spring mounted for biased movement toward and away from the other roll. Also, one of the rolls typically is adjustable to vary the spacing between the rolls. The so-called flax rolls are mounted within the housing of the feeder conveyor, which is relatively narrow, just forward of the thresher.
This modification has several disadvantages. The rolls are hidden from the view of the combine operator, who has no way of knowing when jamming or other problems requiring attention occur. Moreover, the flow rate of the radish pods through the flax rolls, as determined by the feeder conveyor, necessarily must be relatively slow, or otherwise the rolls will not split the pods adequately. The rolls are also poorly accessible, making them difficult and time-consuming to adjust, remove, inspect and install. This problem is particularly troublesome for farmers who frequently use their combines for different applications, some of which require that the rolls be removed. Finally, any given set of rolls generally will fit only the particular feeder housing for which it was designed, making such rolls costly to manufacture and expensive to farmers who must purchase new rolls every time they buy a different combine model.
Accordingly, there is a need for a combine attachment that facilitates the harvesting of virtually defect-free radish seeds at a high rate, and can be universally mounted to most combines in a visible, easily accessible manner.
It is therefore one object of the invention to provide a combine attachment for harvesting radish seed or the like capable of harvesting virtually defect-free radish seed at a high rate.
Another object of the invention is to provide a combine attachment, as aforesaid, that can be universally mounted to most combines.
Still another object of the invention is to provide a combine attachment, as aforesaid, that is visible to the operator so that the harvesting of seeds can be continuously monitored and adjustments made when necessary.
Yet another object of the invention is to provide a combine attachment, as aforesaid, that is easily accessible for repair and adjustment, and easily and quickly mounted to and detached from the combine.
A further object of the invention is to improve the quality of harvested radish seeds or the like.
The foregoing and other objects, features and advantages of the invention will become more readily apparent from the following detailed description which proceeds with reference to the accompanying drawings.